Analytical and Bioanalytical Chemistry

, 395:1737

Analytical approach for characterization of cadmium-induced thiol peptides—a case study using Chlamydomonas reinhardtii

  • Anja Bräutigam
  • Dirk Schaumlöffel
  • Gerd-Joachim Krauss
  • Dirk Wesenberg
Original Paper

DOI: 10.1007/s00216-009-2921-7

Cite this article as:
Bräutigam, A., Schaumlöffel, D., Krauss, GJ. et al. Anal Bioanal Chem (2009) 395: 1737. doi:10.1007/s00216-009-2921-7

Abstract

Phytochelatins (PC) were described earlier to play a role in metal detoxification in Chlamydomonas reinhardtii but were not clearly identified. The focus of this case study was to identify PC synthesized by C. reinhardtii exposed to Cd. Only low intracellular concentrations of cadmium (85 nmol g−1 fresh weight) were sufficient to cause significant changes in thiol peptide pools. Thus, results showed a progressive decline of the glutathione content, accompanied by an induction of phytochelatins. Not only canonic phytochelatins but for the first time also the iso-phytochelatins CysPCn and PC2Ala were identified in this unicellular green alga using electrospray ionization quadrupole time-of-flight tandem mass spectrometry. Additionally, CysPCndesGly, PCndesGly, CysPCnGlu, and PC2Glu were found throughout MS analysis. Also, low abundant PCs could be detected due to the high sample preconcentration combined with little sample amounts (0.3 μL min−1) necessary for electrospray. Identified PCs had a maximum number of 5 γ-glutamyl cysteine (γ-GluCys) units. Thiol peptides of higher molecular masses suggesting PCn with n > 5 could be identified as intermolecular oxidation products of smaller PCs. Thiols may easily be oxidized. Therefore, PCs were reduced prior to MS analysis. Dithiothreitol and tris(2-carboxyethyl) phosphine were compared concerning their reduction effort.

https://static-content.springer.com/image/art%3A10.1007%2Fs00216-009-2921-7/MediaObjects/216_2009_2921_Figa_HTML.gif
Figure

Chlamydomonas reinhardtii synthesizes isoforms of phytochelatins.

Keywords

CadmiumChlamydomonasThiolsIso-phytochelatinsDTTTCEP

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  • Anja Bräutigam
    • 1
  • Dirk Schaumlöffel
    • 2
  • Gerd-Joachim Krauss
    • 1
  • Dirk Wesenberg
    • 1
  1. 1.Martin-Luther-Universität Halle-Wittenberg, Institut für Biochemie und Biotechnologie, Ökologische und Pflanzen-BiochemieHalle (Saale)Germany
  2. 2.CNRS—Université de Pau, Laboratoire de Chimie Analytique Bio-Inorganique et Environnement, UMR 5254 IPREMPauFrance